Archive for the ‘Nutrition’ category

A flurry of recent reports has supported the health benefits of whole-fat milk. Increased dairy fat has been linked to lower rates of diabetes, and to improved cardiovascular health. The traditional advice – that low-fat or skim milk can help reduce weight, and help improve health – may have been based on faulty assumptions about the way ingested dairy fat affects metabolism. These new studies of dairy fit in with a shift away from the “fat is bad” story to a more nuanced “some fat is bad, but other fat is good, and it’s complicated” way of looking at things.

But it’s important to remember that none of the studies driving this change were done in kids. We don’t really know the long-term health impact of full- versus low- versus no-fat milk in infants or children, and there are still some good reasons to think that lower fat dairy might be a good choice for many families.

Until about ten years ago, the AAP recommended full-fat milk starting at age 1. That changed in 2008, when a position statement about cardiovascular health supported the use of reduced-fat dairy products starting at 12 months of age if there were any concerns about overweight or a family history of obesity or heart disease (that would include just about everyone.) This recommendation was based on research showing three things: (1) growth and neurologic function was the same in children raised on low-fat milk (ie, extra fat was not needed for brain and body development); (2) lipid profiles and weights were healthier in children raised on low-fat milk; and (3) children who consumed low-fat milk tended to have healthier diets, overall, than kids drinking whole milk.

That position statement “expired”, as all AAP statements do, 5 years after it was published. Currently, the AAP officially has no position on the relative merits of these varieties of milk. (They do have a position vaguely endorsing chocolate milk in schools, and another position strongly discouraging unpasteurized milk. All AAP policies can be searched here. There are a lot of them.)

The bottom line, now: there really isn’t any solid, new information from studies in children since that 2008 AAP position. Though I agree that the adult studies are compelling, adults and children are very different, especially when looking at metabolism, growth, and the long-term health consequences of dietary choices. For example, milk constitutes a much higher proportion of caloric intake in kids than in adults (children drink more milk, and they’re smaller. Usually.) They need proportionally more calcium and vitamin D and phosphorus for growing bones. And we know overweight children are very likely to continue to struggle to maintain a healthy weight as adults.

The best current evidence in children supports the use of reduced fat milk. If that changes, I’ll let you know.

An interesting new study published in the April, 2016 edition of Pediatrics shows that the birth of a younger sibling is associated with a dramatic decrease in the risk of obesity. I don’t think this ought to sway people towards having more children, but it might offer some insight into other ways to help children keep a healthy weight.

The study recruited families from 1991-1998 (yes, it’s old data. I’m not sure why it took so long to get this written and published.) About 700 children ended up participating. Through in-person visits and phone interviews, the study children were followed from birth through about first grade, tracking who ended up having younger siblings born. The authors then compared children who had younger siblings versus those who remained the only child in the household.

The numbers look strong. Having a younger sibling born between ages 2 to 4 (and especially between 2 to 3 years of age) led to a robust decrease in the upwards trajectory of a child’s BMI. In fact, children who didn’t have a younger child born while they were in preschool had three times the risk of obesity.

Crazy, huh? Three times the risk? Statistically speaking, that’s a big change. This study was unable to show why the birth of a younger sibling helped children keep a more-healthy weight. The authors suggest two possible mechanisms, or ways that having a younger sibling could be protective. Perhaps it changes the way parents feed their children. Other research has shown that ‘restrictive’ feeding practices, like limiting portions or different kinds of foods, are associated with an increased risk of obesity – and maybe having a younger child to look after leaves parents unable to monitor feedings as closely. Allowing young children more control over their food choices does lead to healthier eating and healthier weight gain.

Another idea: children who get younger siblings may themselves become more active, by playing with their little brothers and sisters. They might also become “food leaders”, trying to show their siblings how to eat healthy.

There may be other mechanisms at work here. I’m certainly not convinced I know why the study worked out this way. I do know that healthy weights aren’t about counting calories, only eating “healthy foods”, or buying organic. Hopefully further insights along these lines of this study can help with counseling even single-child families about mealtime and lifestyle routines that can best keep families healthy.

Like this:

A randomized, controlled study from China might be able to teach us something about infant nutrition in the US: iron isn’t just to prevent anemia. It’s essential for motor development, too. And breastfed babies, especially, might not be getting enough.

It’s a clever study. They started with a group of women, who had already been randomized to get either extra iron or a placebo during their pregnancies. After their babies were born, the infants were randomized again to get either an iron supplement or placebo from age 6 weeks to 9 months. So there were really 4 groups, in the end, sorted by whether they had iron during pregnancy/infancy: placebo/placebo, iron/placebo, placebo/iron, and iron/iron. That design was chosen to figure out just when iron supplementation made a difference to infant motor development. The authors postulated that the more iron, taken for longer, the better. They were wrong, but that doesn’t mean we can’t learn from their missed guess.

The babies then had multiple tests of motor development performed. There were about 300 babies in each of the four groups, and the results were consistent among various ways of measuring the babies’ motor skills. Bottom line: iron supplementation during infancy improved motor skills by a considerable margin; iron supplementation during pregnancy didn’t make much difference.

The amount of iron given was smaller than what we’d typically give using a common infant multivitamin with iron in the United States. There were no adverse effects from the iron, which is expected. It is a myth that the ordinary doses of iron given to babies in formula or as a supplement causes constipation or any other problems. I think moms believe that myth because they get constipated during pregnancy, when they’re on higher doses of iron (typically 300 or 325 mg a day), but those doses are way way higher than what babies get (less than 10 mg a day.)

Another important caveat: the study was done in a poor area of rural China, in the Hebei province. Most of the babies, including the once who received iron supplementation, were still iron deficient on their blood tests; 80% of them were breastfeeding at 9 months. So the population isn’t really the same as what we’d see in the developed world. Still, when a safe, cheap, and easy intervention makes a big difference, that’s something to notice.

With this study in mind, should all babies just get a little extra iron? Formula-fed babies probably don’t need an extra supplement, unless they were premature or have other health issues that put them at risk for insufficient iron. But breastfed babies – they almost certainly need extra iron, especially by 4-6 months of age when their storage iron from birth starts to run down. Some complementary foods offer good iron, like fortified cereals, meats, and eggs, but some four month old infants don’t seem quite ready for those kinds of meals yet (many do, though—give it a try!) There’s also some evidence that you can prevent iron deficiency in infants by delaying clamping of the umbilical cord for a few minutes after birth. Will that help improve motor development, as seen with the supplements used in this study? Maybe.

There are really no important down sides to giving an iron supplement to infants. In fact, the only one I can think of is that they might stain teeth, so rinse the mouth or wipe teeth afterwards. A typical dose is one dropper of an iron-containing infant vitamin once a day, but check with your doctor for the best dose for your baby. And remember, with those improved motor skills, Junior might be able to get the cap off herself. So keep iron, vitamins, and all other meds well away from the reach of children.

Like this:

An exhaustive new review should provide reassurance for nursing moms: many medications are safe for you to take, and genuinely serious reactions are very rare. Moreover, most serious reactions that do occur are to just a handful of medications. Common sense can be a good guide to keeping nursing babies safe when their moms take medication.

In this study, from February 2016, the authors did a truly comprehensive search of the literature for all studies and case reports of problems caused by medications in breast milk. The same authors had done a similar study in 2002, and decided it was time for an update.

Some of the findings:

About 60% of reported reactions occurred during the first month of life; and 80% during the first two months. This makes sense—the youngest babies consume the most milk per weight, and also have the least ability to metabolize medications.

70% of adverse reactions were to medications that affect the brain, including narcotic pain medicines, antidepressants, and antipsychotic medications.

All of the deaths reported (there were only 2) involved one or more narcotic pain medications.

The use of multiple nervous system depressants at the same time increased the risk of serious reactions.

The bottom line: be careful especially with the youngest babies, especially when using multiple medicines, and especially when using medicines like narcotics that are known to cause slow and shallow breathing. That doesn’t mean nursing moms can’t take these medicine, but it does mean that they ought to take advantage of non-narcotic pain medicines, first, and if they do take narcotics their babies need to be monitored closely. A “pump and dump” strategy can be employed if mom needs potent pain medicines for a short time. It is not reasonable to expect nursing moms to live with untreated pain.

A great resource for nursing moms and the doctors who give them advice is the Lactmed database from the National Institutes of Health. You can look up just about any medication there, and see what studies are available to give you real and reliable information on milk transfer and potential issues with nursing babies. Some of the information is quite technical, but it’s better than the vague handwaving found in other places.

Speaking of which: one of the worst places to look for safety info for breastfeeding moms are the official “product inserts” of medications. They pretty much always say that nursing moms can never take any medicine (I don’t think they’re allowed to eat any food, either. Just water and rocks. Safety first!) Remember: product inserts are written by lawyers, for lawyers. They’re there to fulfill the crazy byzantine regulatory framework of the FDA. And to ward off lawsuits, and possibly vampires too. They’re not there to give parents or doctors useful information.

The health of moms is important, too. Often, moms stop taking their own medications out of fear that it may harm their nursing baby. Reviews like this, looking at what’s actually published and documented, provide some useful reassurance for moms and babies alike.

“Breast is best” is a simple, catchy phrase—but to be honest, it’s one that should be followed by a bunch of asterisks and qualifiers. Some mother-baby pairs have a hard time with nursing, and need support and understanding (rather than a simple dismissal of their concerns.) And breast milk, we know, isn’t a great source of absorbable iron, which is especially an issue for premature babies. But the biggest drawback of human breastmilk, compared with commercial formula, is that it is an inadequate source of vitamin D.

A new study shows that this doesn’t have to be the case. Perhaps insufficient vitamin D isn’t really a fundamental problem with breast milk, but a problem with mom’s vitamin D intake.

Backing up a second – we’ve known for a long time that breast-fed babies are much more at-risk for nutritional rickets than formula-fed babies. This is especially true for families with dark skin. Rickets is caused by insufficient vitamin D, and can lead to poor growth, bowed limbs, and other health problems. For most of human history our vitamin D came from sunlight exposure. The skin of babies and mothers can manufacture vitamin D, though it requires sunlight to do it. Darker skin is less efficient at making vitamin D than lighter skin.

To combat the risk of insufficient vitamin D in breast-fed babies, the AAP has recommended a daily vitamin D supplement, starting from birth. In practice, this recommendation is followed maybe 20% of the time. Parents don’t like to give their newborns medicine, and I think pediatricians are reluctant to focus on the possible inadequacies of human breast milk.

In the current study, researchers sought to determine if giving higher doses of vitamin D to nursing moms could result in enough vitamin transfer in their milk. 334 mother-infant pairs were recruited, and randomized into three groups. In group one, moms were given an ordinary vitamin supplement, and their babies a vitamin D supplement (400 IU/day, matching the current recommendation.) In group 2, the babies were given no extra D, but moms took 2400 IU/day; in group three, moms were given 6400 IU each day. Babies and moms underwent regular blood and urine tests to see if these doses resulted in good vitamin D levels in the babies, and to see if these doses caused any metabolic problems with vitamin D, phosphorus, or calcium metabolism.

There was a relatively high drop-out rate—of the original 334 pairs, just 148 stuck with the plan for exclusive breastfeeding, and were thus able to complete the trial (families who discontinued breastfeeding or added formula supplements were not included in the final analysis.)

All of the babies who received regular supplementation had robust vitamin D levels and normal biochemical testing – we know, if that 400 IU a day for babies is given, it works. That was group 1. Group 2, where moms were given vitamin D 2400 IU/day, was a failure—they actually stopped this arm of the study early, because many of the babies in this group did not have adequate vitamin D levels on their blood tests. But the babies in group 3 – who themselves received no direct vitamin D supplements, but whose moms got 6400 IU/day—did as well as group 1, with perfectly good vitamin D levels and no evidence for any side effects or problems. And, bonus, their moms also benefitted, with normal vitamin D levels and no side effects.

A reasonable question, though—is 6400 IU of D a day safe for moms to take? A prior guideline from the Institute of Medicine had suggested an upper limit of 2000 IU/day (though that has since been increased to 4000); the Endocrine Society now sets their upper limit at 10,000. During the past decade many studies have used adult D supplementation in the range of thousands of units per day, and according to the authors of this paper not a single adverse event was observed.

This study supports a safe alternative for families, and perhaps one that’s easier to do. Moms are used to taking prenatal vitamins, and continuing to take them while nursing. Adding 6,000 IU of D to the typical 400 in a prenatal isn’t expensive, and seems to be safe and effective at making sure their babies get enough D. Breast milk can have enough D – but only if mom gets her own supplement.

A simple, safe, and cheap intervention looks like a good way to help fight obesity in our schools. But not by very much.

A study published January 2016 in JAMA Pediatrics, “Effect of a school-cased water intervention on child body mass index and obesity”, looked at the effects of installing new water dispensers in New York City school cafeterias. 1227 schools, including 1 065 562 students, participated in the observational study, which tracked student weights and BMIs, comparing trends before and after the new equipment was installed.

Those new dispensers are called “water jets” in the study, and I *think* they’re just those typical water cooler things that offices use, with a big jug of water on top and a little flappy valve to get cooled water into a cup below. The study description says they both chill and oxygenate the water “to keep it tasting fresh”, and cost about $1000 bucks each. Furthermore, they “are relatively easy to use” (pretty clever, those New York kids.) The authors pointed out that participants were weighed and measured by PE coaches, whose scale-using skills have “previously been found reliable” (pretty clever, those New York coaches.)

The results: after these water jets became available, there was a statistically significant drop in BMI of about 0.025 points (it was just a touch more effective in boys than girls), and the percentage of children in the schools who were overweight dropped by .6-.9%. (from about 39% to about 38%).

I know, not very impressive. The statistics are solid—whether the authors looked at trends over entire schools, or at trends among individual students before and after water jet availability, these weight parameters did drop. And the drop is, technically, statistically valid and real. That’s how it’s been reported in the media. The New York Daily News said “Water machines available in schools can help kids lose weight.”

But the drop really wasn’t very much. Going from 39% to 38% overweight is good, but I think we ought to try to do better. You can lead a student to water, but studies like this show it’s hard to make them actually lose weight.

It seems like every time my (almost 6 year old) child gets sick, a line forms of sales-friends who try to convince me that ‘ever since they gave their child Juice Plus+, they haven’t been sick.’ Could you give your opinion from your medical perspective? Personally, I prefer to give Flintstones vitamins with the iron, but I’d love to have a better understanding of the best vitamins to give.

Vitamins are an interesting psycho-sociological phenomenon. We know that we need them—if you don’t get any vitamin C, you’re fairly quickly going to suffer a fairly horrendous death—but we barely need much of any of them. Just a few milligrams, here and there, not even every day, will keep you and your children chugging along just fine. But, of course, being the creatures that we are, many people seem to view vitamins as having magical abilities. If a tiny bit is good, a whole lot more is better. Or, since some vitamins are involved in energy metabolism, taking a whole lot of them will give you more energy. Or cure a hangover, or make you invulnerable to colds, the flu, and presidential debates. Magic!

The truth is, vitamins are just chemicals. Like any other chemical, once you swallow it your body doesn’t know or care if it came from a leaf or a pill; and it certainly doesn’t care if it came from a cheapo pill or an expensive, name-brand pill sold by one of your “sales-friends.” A vitamin is a vitamin. If you think your child needs one (and he probably doesn’t), take an inexpensive one and save up some money to buy more yummy fresh fruits and veggies. Because those, he could probably use. A pill that claims to be a replacement for real fruits and real veggies? Sold as part of a multilevel marketing scheme? Please.

What about vitamins for parents? Several good studies in adults show that people who regularly take multivitamins have poorer health. Makes you wonder about all of that vitamin marketing.

Share this:

Like this:

This site is for informational purposes only. Communicating via this board does NOT create a doctor-patient relationship. If you have a medical concern specific to your child, contact your own pediatrician.

Unauthorized use and/or duplication of this material without written permission from the blog owner is prohibited. Excerpts and links may be used, provided that full and clear credit is given to Roy Benaroch, MD and www.PediatricInsider.com with appropriate and specific direction to the original content.